Endotoxin-induced formation of thrombin and APC. A 40-mg dose of E coli endotoxin/kg body weight was injected intraperitoneally into wild-type (wt), heterozygous FV Leiden (VL^+/–), homozygous FV Leiden (VL^+/+), and homozygous TMPro mice (n = 8 per group). After 2 hours, 20 μg human PC was infused through the femoral vein, and 10 minutes after, blood was harvested for determination of TAT and APC levels in plasma. *P < .05. Error bars indicate standard deviation.